Separation and Sensitive Detection of α -Lactalbumin and β -Lactoglobulin by Capillary Zone Electrophoresis

Abstract

α-lactalbumin and β-lactoglobulin are main impurities in the lactose products extracted from whey,which may cause allergy.Therefore,the separation and detection of race α-lactalbumin and β-lactoglobulin are of great importance to food and pharmaceutical industry.In this work,a simple,fast,sensitive and reproducible capillary zone electrophoresis(CZE) method has been developed for this purpose.After simple sample preparation procedure,α-lactalbumin and β-lactoglobulin can be baseline separated within 2 minutes under following conditions:25 mM phosphate buffer at pH 7.0,+ 30 kV applied voltage,25 ℃ capillary temperature,205 nm UV detection,and sample injection at 50 mbar for 10 s。The limit of detection(LOD) at 3 times of S/N is 3.0 and 12 mg/L for α-lactalbumin and β-lactoglobulin,respectively.The repeatability(RSD,n=6) is below 1% for migration time and below 6% for peak area.These data qualified the method to the analysis of real lactose samples.The proposed method also shows a great potential in other fields of food and pharmaceutical industry.